Ever wonder how fast your auto tranny can overheat?

Do a power brake. Foot on the brake, put the transmission in 1st gear. Bring the rpms to 1500. Thats how I got my fluid temps up to check my fluid level after installing my Tru cool 4454. I also bypassed the factory cooler. It took about a minute to get the temp to operating range.

 

Wouldn't recommend anything other than Toyota's fluid or Amsoil. Amsoil synthetic will probably lubricate a bit better and handle the heat better (wont break down as fast) but it wont really change any temps noticeably. Better to just get an aux cooler.

 

So something like mobile 1 atf isn't a good idea? As far as trans coolers go, the bigger the better or will a larger surface area make no difference?

About how much is amsoil per quart?

 

Larger surface area and more capacity is better.

You need to look into how a standard torque converter works to understand how a locking one works. It's very similar to a viscous clutch but you have one side driving fluid at the other though a 'stator'. They're not fixed together, one side is fixed to the engine and the other the trans and they only move through directing fluid --- when you don't have a lockup clutch.

The way the fluid moves causes it to heat up a lot when your impeller and your turbine are at vastly different speeds. This is why the lockup lowers the temp.

http://auto.howstuffworks.com/auto-parts/towing/towing-capacity/information/torque-converter.htm

Just fyi...

 

Amsoil can be very expensive. Dont recommend Mobil 1, no (or any other brand for that matter). Toyota's fluid is probably the best you can get (its very good) excluding, maybe, amsoil. I don't think its worth it honestly and would stick with Toyota's fluid. They dont go cheap on these things.

 

best thing is OEM or equivalent fluid and frequent oil drain and fill, Better oil cooler, don't punish your vehicle while towing specially on grades.

torque converter explained here:
https://www.youtube.com/watch?v=z5G2zQ_3xTc

 

Not to bring up an old thread, but I used to tow in OD, because in florida we're mostly all flat, so there's no gear hunting. Is that bad?

 

As long as your clutch stays locked, you're fine.

 

Our trucks don't have OD button!

 

No, but you have a spot to turn off the OD,when you're in d, slide the shifter to the left and it's in 4 (The trans will only shift from 1-4, so OD is off), down to 3 (trans will only shift from 1-3) down to 2 (trans will only shift from 1st to 2nd) and 1 (trans is locked in 1st).

 

Are you saying fifth gear is overdrive? Never heard it called that before.

 

Yes, the gearing in 5th gear is Higher than 1:1 (I think it's .6x:1, it's .85:1 for the 6 speed)

 

I'm totally confused now.

 

There was a time ppl never heard it called fifth gear before

 

Whoops, meant that 5th gear is higher (numerically lower) than 1:1

A overdrive gear means that the gear ratio is 1:1 or higher, 5th gear is geared .6x:1 , 6th gear on the 6spd is geared .85:1, hence 5th gear on the auto trans and 6th gear on the manual trans are OD.

 

The jeepers with nine gears must be going crazy!

 

Underdrive gears mean the trans is spinning slower than the engine. Good for making torque (multiplies or increases torque output) but bad for MPGs. Any gear smaller than 1:1 is an underdrive gear.

Overdrive gears mean the trans is spinning faster than the engine. Horrible for making torque (reduces torque output) but good from MPGs. Any gear that is taller than 1:1 is an OD gear.

Many cars also have a 1:1 gear where the engine and trans are spinning at the same speed. (generally the 4th gear in a 5 sp or 5th gear in a 6 sp).

Im pretty sure 1:1 isnt an OD gear but we may be splitting hairs

 

So basically if I tow in overdrive, and my clutch is staying locked I'm ok. But if it's too much weight/a grade and my clutch keeps unlocking I just need to take it out of OD?

 

That's correct.

 

^ This

Also would want to consider an aux cooler if you tow a lot. You are still putting more stress/heat in the lower gears.